Index: trunk/ippTasks/detrend.stack.pro
===================================================================
--- trunk/ippTasks/detrend.stack.pro	(revision 14630)
+++ trunk/ippTasks/detrend.stack.pro	(revision 14681)
@@ -115,5 +115,5 @@
     # look for new images in detPendingStackedImfile
     book getpage detPendingStackedImfile 0 -var pageName -key pantaskState INIT
-    if ($pageName == NULL) break
+    if ("$pageName" == "NULL") break
 
     book setword detPendingStackedImfile $pageName pantaskState RUN